The present invention relates to a treatment apparatus, and more particularly, to a target for generating carbon ions and a tumor treatment apparatus using the same.
Methods for radiotherapy may include X-ray treatments, electron beam treatments, and ion beam treatments. Among these, since the X-ray treatments are the cheapest treatment methods which can be realized using the simplest device, the X-ray treatments are being most commonly used at the present day. Although it has been proven in 1950's that tumors can be treated by accelerating electrons using an accelerator to inject the electrons into the tumors, with the miniaturization of an electron accelerator in 1980's, the electron beam treatments have been taken over as one method for radiotherapy. In the X-ray treatments or the electron beam treatments, hydrogen bonds within cancer cells can be cut to destroy DNAs of the cancel cells. However, side effects in which healthy cells existing within the traveling path of X-rays or electron beams are seriously damaged may occur. Technologies such as intensity-modulated radiation therapy (IMRT), tomo therapy, and cyber knife have been developed as methods for reducing the radiation exposure of normal cells. However, the technologies can not completely solve the above-described side effects.
The ion beam treatments are in the spotlight as treatment methods which can mitigate the side effects due to the X-ray treatments or the electron beam treatments. To allow the ion beam to penetrate a material, the ion beam should be accelerated to have high velocity, like the electrons. Even though the ion beam is gradually decreased in velocity when the ion beam penetrates a certain material, the ion beam is subject to the most energy loss of ionizing radiation just before the ion beam is stopped. This phenomenon is called a Bragg peak after William Henry Bragg, which discovered the phenomenon in 1903. Thus, in a case of such an ion beam treatment, malignant tumors may be selectively and locally treated when the ions are precisely controlled in velocity.
In aspect of acceleration energy, the lightest hydrogen ions (i.e., protons) of ions have been considered as a material for ion beam treatments. However, carbon ion treatments are in the spotlight as tumor treatment methods in recent years after it is known that carbons have superior biological effects than protons. For example, according to researches, carbon has a cancer cell destruction rate greater by about 2.8 times than that of protons and results in a cancer recurrence rate less by about 2.5 times than that resulted from X-rays or protons. In general, carbon ions may be accelerated by a synchrotron or cyclotron device. However, since the synchrotron or cyclotron device is large and expensive, commercial applicability thereof is low.